Stuttering has a lifetime incidence (i.e., percentage of adults who ever stuttered) of nearly 5% and significantly impacts the academic, emotional, social, and vocational achievements, development and potential of individuals who stutter (see Bloodstein &Bernstein Ratner, 2008). However, seventy-eighty percent of those affected discontinue (e.g., Yairi &Ambrose, 1999) without significant formal treatment (i.e., "unassisted" recovery). For the remaining children (i.e., approximately 1% of children who continue to stutter after 6 years of age), the negative impact of stuttering on their lives and daily activities can be significant. There is a strong need, therefore, to determine variables that may initiate/cause, exacerbate or perpetuate stuttering to develop more efficient, effective empirically-based approaches to diagnosis and treatment. Further, as Yairi (1993) noted, "Because advanced stuttering is markedly different from the incipient form...attempts to infer its [stuttering's] etiology and nature or to prescribe treatment for children who stutter based on models derived from adult stutterers are indefensible" (Conture, 1991;Yairi, 1990;p.198). Thus, it is imperative to examine variables in the period during which stuttering typically begins. To address this imperative, we propose a longitudinal study of preschool-age children who stutter, with emphasis on how emotion and speech-language processes contribute to developmental stuttering. Building on Monroe and Simons'(1991) etiological notion of diathesis-stress interactions, the applicants'conceptual model proposes that dual diatheses (i.e., emotional and/or speech-language vulnerabilities) are activated by environmental stressors (e.g., changes, differences, novelty in structure and/or changes in need to spontaneously generate speech-language) to cause stuttering. This model assumes that a finite number of combinations of emotional and/or speech-language variables contribute to meaningful differences between children who do and do not stutter, as well as between children who recover and those who persist. The proposed project builds on our preliminary findings and theoretical model, longitudinally, to relate emotional and speech-language to developmental stuttering, using multiple methods (i.e., observational, standardized testing, parent-report, and psychophysiology) that assess our major constructs of emotion and speech-language. This interdisciplinary investigation - involving collaboration between developmental psychology and speech-language pathology - should help determine whether children at the onset of stuttering differ from their normally fluent peers on emotion and speech-language variables and whether these differences, over time, predict which children will and will not recover. Findings from this longitudinal investigation will help ground the study of stuttering within the broader context of emotional and speech- language development and help focus future research on issues that inform diagnostic and treatment protocols for childhood stuttering. PUBLIC HEALTH RELEVANCE: Stuttering has a lifetime incidence (i.e., percentage of adults who stuttered at some point) of nearly 5% and significantly impacts the academic, emotional, social, and vocational achievements, development and potential of individuals who stutter (see Bloodstein and Bernstein Ratner, 2008;Conture, 1996;Yairi, 1997). For the remaining children (i.e., the approximately 1% of children who continue to stutter after 6 years of age), the negative impact of stuttering on their lives and daily activities can be significant. Thus, there is a strong need to determine those variables that may initiate/cause, exacerbate or perpetuate stuttering - as this project will attempt to do - in order to eventually develop more efficient, effective empirically-based approaches to the diagnosis and treatment of stuttering.